Validation of vesical imaging reporting and data system for assessing muscle invasion in bladder tumor

Multiparametric MRI for Bladder Cancer: A Practical Approach to the Clinical Application of VI-RADS

Multiparametric MRI of the bladder is highly accurate in the detection and local staging of bladder cancer. The Vesical Imaging Reporting and Data System (VI-RADS) scoring system has improved the diagnostic accuracy, reproducibility, and interpretability of bladder MRI in the assessment of the invasion of the muscularis propria. There are several technical details concerning bladder MRI that need to be strictly applied to obtain the highest possible diagnostic potential from the MRI. In addition, image evaluation, accurate interpretation, and reporting need to be standardized to optimize diagnostic accuracy and interreader agreement. This review describes the patient population for bladder MRI and discusses, with a practical approach, the correct acquisition protocol for optimal image quality using VI-RADS with reporting tips, pitfalls, and challenges for its clinical application. This review also discusses the latest evidence, clinical implications, current controversies, and future challenges, including gaps in knowledge, of the VI-RADS scoring system.

Evaluating the concordance between Vesical Imaging Reporting and Data System scores and bladder tumor histopathology

Objective

This study aimed to assess the local staging of bladder tumors in patients utilizing preoperative multiparametric MRI (mpMRI) and to demonstrate the clinical efficacy of this method through a comparative analysis with corresponding histopathological findings.

Methods

Between November 2020 and April 2022, 63 patients with a planned cystoscopy and a preliminary or previous diagnosis of bladder tumor were included. All participants underwent mpMRI, and Vesical Imaging Reporting and Data System (VI-RADS) criteria were applied to assess the recorded images. Subsequently, obtained biopsies were histopathologically examined and compared with radiological findings.

Results

Of the 63 participants, 60 were male, and three were female. Categorizing tumors with a VI-RADS score of >3 as muscle invasive, 84% were radiologically classified as having an invasive bladder tumor. However, histopathological results indicated invasive bladder tumors in 52% of cases. Sensitivity of the VI-RADS score was 100%; specificity was 23%; the negative predictive value was 100%; and the positive predictive value was 62%.

Conclusion

The scoring system obtained through mpMRI, VI-RADS, proves to be a successful method, particularly in determining the absence of muscle invasion in bladder cancer. Its efficacy in detecting muscle invasion in bladder tumors could be further enhanced with additional studies, suggesting potential for increased diagnostic efficiency through ongoing research. The VI-RADS could enhance the selection of patients eligible for accurate diagnosis and treatment.

Performance and Clinical Implications of VI-RADS in detecting muscle invasion in bladder tumors: A prospective observational study

Introduction

Bladder cancer staging is pivotal for guiding therapeutic decisions. In this study, the primary objective was to assess the diagnostic accuracy of multiparametric magnetic resonance imaging (mpMRI), The study aimed to classify bladder tumors as either nonmuscle-invasive bladder cancers or muscle-invasive bladder cancers (MIBC) using the Vesical Imaging Reporting and Data System (VI-RADS) scoring. A secondary objective of the study focused on the accuracy of biparametric magnetic resonance imaging (bpMRI) in comparison to mpMRI.

Methods

Thirty-three patients with bladder tumors were enrolled and underwent both mpMRI and bpMRI scoring assessments. VI-RADS scores were assigned and subsequently compared with histopathological findings posttransurethral resection of bladder tumor., Statistical measures included sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy for VI-RADS scores at cutoff thresholds of ≥4 and 5.

Results

MpMRI at a VI-RADS cutoff of ≥4 yielded an 83.33% sensitivity and 100% specificity, with a diagnostic accuracy of 90.91%. At a cutoff of 5, sensitivity was 100%, specificity was 77.27%, and diagnostic accuracy was 84.85%. bpMRI at a cutoff of ≥4 showed an 80% sensitivity and 100% specificity, with diagnostic accuracy matching mpMRI at 90.91%.

Conclusions

This prospective analysis demonstrates that VI-RADS scoring with mpMRI provides reliable diagnostic accuracy for bladder cancer staging. mpMRI exhibits high sensitivity and specificity at a cutoff of ≥ 4, making it a robust tool for MIBC detection. bpMRI is an effective alternative in select patients. The study validates the use of VI-RADS scoring in clinical practice for effective treatment planning.

[Application of Magnetic Resonance Imaging Report Combined With VI-RADS Bi-Parametric and Multi-Parametric Scoring Systems in Bladder Cancer Diagnosis]

Objective

To verify by retrospective analysis the performance of applying dual-parametric (T2 weighted image [T2WI] and diffusion weighted image [DWI]) and multi-parametric (T2WI, DWI, and dynamic contrast enhance [DCE]) evaluation systems of Vesical Imaging-Reporting and Data System (VI-RADS) in the magnetic resonance imaging (MRI) diagnosis of bladder cancer.

Methods

The imaging and clinical data of bladder cancer patients who underwent bladder MRI examination in the Department of Urology of our hospital between January 2020 and December 2021 were collected. A total of 215 bladder cancer patients, among whom there were 183 males and 32 females with an average age of (67.60±11.42) years, were included. The bladder cancer diagnosis of all the cases was verified by pathology analysis of tissue samples. Two radiologists, who were double-blinded, scored multiple sequences separately. Then, a comparative analysis was made on the diagnostic performance of dual-parametric and multi-parametric VI-RADS diagnostic scores. The diagnostic test with receiver operator characteristic (ROC) curves and Cohen's Kappa were used to evaluate the diagnostic efficacy and consistency.

Results

The area under the curve (AUC) and 95% confidence interval (CI) of the multi-parametric VI-RADS evaluation system by the two radiologists in the overall population were 0.878 (0.830-0.925) and 0.856 (0.805-0.907), while those for the bi-parametric VI-RADS evaluation system were 0.889 (0.844-0.934) and 0.856 (0.805-0.907), showing no statistically significant difference. No significant difference was observed in the subgroup analysis of patients who underwent transurethral resection of bladder tumor (TURBT). Furthermore, the Kappa values for inter-rater agreement between of the two radiologists were 0.694 and 0.546 (with the VI-RADS score≥3 defined as being positive) and 0.693 and 0.712 (with the VI-RADS score≥4 defined as being positive) in multi-parametric and bi-parametric evaluation, respectively (all P<0.001).

Conclusion

The bi-parametric VI-RADS scoring system can achieve a diagnostic efficacy comparable to that of the multi-parametric scoring system, offering an alternative to patients who are unable to undergo contrast-enhanced MRI due to allergic reaction to contrasts.

Performance of VI-RADS in predicting muscle-invasive bladder cancer after transurethral resection: a single center retrospective analysis

PURPOSE

To assess VIRADS performance and inter-reader agreement for detecting muscle-invasive bladder cancer (MIBC) following transurethral resection of bladder tumor (TURBT).

METHODS

An IRB-approved, HIPAA-compliant, retrospective study from 2016 to 2020 included patients with bladder urothelial carcinoma who underwent MRI after TURBT, and cystectomy within 3 months without post-MRI treatments. Three radiologists blinded to pathology results independently reviewed MR images and assigned a VI-RADS score. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of VI-RADS were assessed for diagnosing MIBC using VI-RADS scores ≥ 3 and ≥ 4. Inter-reader agreement was assessed using Gwet's agreement coefficient (AC) and percent agreement.

RESULTS

The cohort consisted of 70 patients (mean age, 68 years ± 11 [SD]; range 39-85; 58 men) and included 32/70 (46%) with MIBC at cystectomy. ROC analysis revealed an AUC ranging from 0.67 to 0.77 and no pairwise statistical difference between readers (p-values, 0.06, 0.08, 0.97). Percent sensitivity, specificity, PPV, NPV and accuracy for diagnosing MIBC for the three readers ranged from 81.3-93.8, 36.8-55.3, 55.6-60.5, 77.3-87.5, and 62.9-67.1 respectively for VI-RADS score ≥ 3, and 78.1-81.3, 47.4-68.4, 55.6-67.6, 72.0-78.8 and 61.4-72.9 respectively for VI-RADS score ≥ 4. Gwet's AC was 0.63 [95% confidence interval (CI): 0.49,0.78] for VI-RADS score ≥ 3 with 79% agreement [95% CI 72,87] and 0.54 [95%CI 0.38,0.70] for VI-RADS score ≥ 4 with 76% agreement [95% CI 69,84]. VIRADS performance was not statistically different among 31/70 (44%) patients who received treatments prior to MRI (p ≥ 0.16).

CONCLUSION

VI-RADS had moderate sensitivity and accuracy but low specificity for detection of MIBC following TURBT, with moderate inter-reader agreement.

Clinical application of bladder MRI and the Vesical Imaging-Reporting and Data System

Diagnostic work-up and risk stratification in patients with bladder cancer before and after treatment must be refined to optimize management and improve outcomes. MRI has been suggested as a non-invasive technique for bladder cancer staging and assessment of response to systemic therapy. The Vesical Imaging-Reporting And Data System (VI-RADS) was developed to standardize bladder MRI image acquisition, interpretation and reporting and enables accurate prediction of muscle-wall invasion of bladder cancer. MRI is available in many centres but is not yet recommended as a first-line test for bladder cancer owing to a lack of high-quality evidence. Consensus-based evidence on the use of MRI-VI-RADS for bladder cancer care is needed to serve as a benchmark for formulating guidelines and research agendas until further evidence from randomized trials becomes available.

A novel predict method for muscular invasion of bladder cancer based on 3D mp-MRI feature fusion

Objective. To assist urologist and radiologist in the preoperative diagnosis of non-muscle-invasive bladder cancer (NMIBC) and muscle-invasive bladder cancer (MIBC), we proposed a combination models strategy (CMS) utilizing multiparametric magnetic resonance imaging.Approach. The CMS includes three components: image registration, image segmentation, and multisequence feature fusion. To ensure spatial structure consistency of T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI), and dynamic contrast-enhanced imaging (DCE), a registration network based on patch sampling normalized mutual information was proposed to register DWI and DCE to T2WI. Moreover, to remove redundant information around the bladder, we employed a segmentation network to obtain the bladder and tumor regions from T2WI. Using the coordinate mapping from T2WI, we extracted these regions from DWI and DCE and integrated them into a three-branch dual-channel input. Finally, to fully fuse low-level and high-level features of T2WI, DWI, and DCE, we proposed a distributed multilayer fusion model for preoperative MIBC prediction with five-fold cross-validation.Main results. The study included 436 patients, of which 404 were for the internal cohort and 32 for external cohort. The MIBC was confirmed by pathological examination. In the internal cohort, the area under the curve, accuracy, sensitivity, and specificity achieved by our method were 0.928, 0.869, 0.753, and 0.929, respectively. For the urologist and radiologist, Vesical Imaging-Reporting and Data System score >3 was employed to determine MIBC. The urologist demonstrated an accuracy, sensitivity, and specificity of 0.842, 0.737, and 0.895, respectively, while the radiologist achieved 0.871, 0.803, and 0.906, respectively. In the external cohort, the accuracy of our method was 0.831, which was higher than that of the urologist (0.781) and the radiologist (0.813).Significance. Our proposed method achieved better diagnostic performance than urologist and was comparable to senior radiologist. These results indicate that CMS can effectively assist junior urologists and radiologists in diagnosing preoperative MIBC.

Progress of Multiparameter Magnetic Resonance Imaging in Bladder Cancer: A Comprehensive Literature Review

Magnetic resonance imaging (MRI) has been proven to be an indispensable imaging method in bladder cancer, and it can accurately identify muscular invasion of bladder cancer. Multiparameter MRI is a promising tool widely used for preoperative staging evaluation of bladder cancer. Vesical Imaging-Reporting and Data System (VI-RADS) scoring has proven to be a reliable tool for local staging of bladder cancer with high accuracy in preoperative staging, but VI-RADS still faces challenges and needs further improvement. Artificial intelligence (AI) holds great promise in improving the accuracy of diagnosis and predicting the prognosis of bladder cancer. Automated machine learning techniques based on radiomics features derived from MRI have been utilized in bladder cancer diagnosis and have demonstrated promising potential for practical implementation. Future work should focus on conducting more prospective, multicenter studies to validate the additional value of quantitative studies and optimize prediction models by combining other biomarkers, such as urine and serum biomarkers. This review assesses the value of multiparameter MRI in the accurate evaluation of muscular invasion of bladder cancer, as well as the current status and progress of its application in the evaluation of efficacy and prognosis.

Can magnetic resonance imaging differentiate muscle invasion (T2) and lamina propria invasion (T1) urothelial carcinoma of the bladder? A systematic review and meta-analysis of Vesical Imaging-Reporting and Data System accuracy

Background

Vesical Imaging-Reporting and Data System (VI-RADS) was developed as a structured reporting tool to anticipate the possibility of muscle invasion. This study is aimed to investigate the diagnostic accuracy of VI-RADS for discriminating T2 from T1 bladder cancer.

Materials and methods

Scopus, Web of Science, PubMed, and Embase were searched on October 4, 2021, for studies with the following characteristics: (1) bladder cancer patient population, (2) VI-RADS as an index test, (3) retransurethral resection of bladder tumor/cystectomy as a reference, and (4) adequate VI-RADS score data for T1 and T2 lesions. The analyses were performed using the binary regression model of MIDAS in Stata.

Results

Six studies with 624 magnetic resonance imaging reports were included. The receiver operating characteristics curve for differentiation of T2 from T1 bladder cancer showed an area under the curve of 0.93 (95% confidence interval [CI], 0.91-0.95) for a VI-RADS ≥3 and 0.75 (95% CI, 0.71-0.79) for a VI-RADS ≥4. A VI-RADS ≥3 showed high sensitivity of 93% (95% CI, 85%-97%), specificity of 61% (95% CI, 30%-86%), positive likelihood ratio of 2.4 (95% CI, 1.1-5.3), and negative likelihood ratio of 0.11 (95% CI, 0.05-0.24). A total of 10.4% of T2 lesions were scored as VI-RADS 2, while 10% of T1 lesions were scored as VI-RADS 4 or 5.

Conclusions

The VI-RADS ≥3 has high accuracy and sensitivity for detecting muscle invasion in borderline populations of T1 or T2 bladder cancer. Thus, the VI-RADS could be a good non-invasive screening test for the detection of T2 urothelial lesions.

Is There A Benefit of Restaging Transurethral Resection of Bladder Tumor Prior to Radical Cystectomy With or Without Neoadjuvant Chemotherapy?

BACKGROUND

One of the best predictors of positive outcomes in bladder cancer (BC) is pT0 following radical cystectomy (RC). Discordance between clinical and pathologic staging affects decision-making in patients with clinical absence of disease (cT0).

OBJECTIVES

We sought to determine whether a restaging transurethral resection of bladder tumor (re-TURBT) improves clinical staging accuracy relative to pathologic stage RC in patients treated with neoadjuvant chemotherapy (NAC) versus those who did not receive NAC.

METHODS

We queried our prospectively maintained IRB approved institutional database to identify 129 patients who underwent RC from 2013 to 2019 with a re-TURBT prior to RC. 53 patients were treated with NAC between their initial and re-TURBT and 76 patients were not treated with NAC.

RESULTS

The overall upstaging rate from re-TURBT to RC was 34.9%. There was no significant difference in the upstaging rate between the NAC and no-NAC groups - 31.0% vs. 37.0%, respectively. In patients who were cT0 on re-TURBT, the NAC group did not show a significantly greater rate of pathologic clinical CR (pT0) than the no NAC group - 38.5% vs. 37.5%, respectively. Re-TURBT with staging < rT2 as a predictor for absence of MIBC on pathologic staging (

CONCLUSIONS

Re-TURBT after NAC does not show statistically significant improvement in staging accuracy relative to pathologic stage at RC compared to re-TURBT in patients not treated with NAC.

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Key Words

• Bladder Cancer
• neoadjuvant chemotherapy
• radical cystectomy
• transurethral resection of bladder tumor

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Affiliation(s)

Justin P Mehr Scott Department of Urology, Dan L Duncan Cancer Center, Baylor College of Medicine, Houston, TX, USA
Jenna N Bates Scott Department of Urology, Dan L Duncan Cancer Center, Baylor College of Medicine, Houston, TX, USA
Seth P Lerner Scott Department of Urology, Dan L Duncan Cancer Center, Baylor College of Medicine, Houston, TX, USA

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To determine correlation between VIRADS scoring and pathological staging in bladder cancer: A prospective study and review of literature

The development of standardized reporting systems is of paramount importance in medical-imaging. Based on the "RADS" methodology, PIRADS and BI-RADS have been successfully used. The management of bladder cancer (BC) depends on the stage at the time of identification. Accurate assessment of the muscle-invasive stage can alter therapies that are radically different. MRI can accurately diagnose this in a standardized manner (Vesical Imaging-Reporting and Data System: VIRADS) and spare additional procedures. The aim of the study is to determine diagnostic accuracy of VIRADS scoring in evaluation of muscle invasiveness in patients with BC. This study was conducted in a single center over a period of 2 years from April 2020. A total of 76 patients with bladder SOL/diagnosed BC were included. Final VIRADS scoring was calculated and compared with histopathological report.76 patients were evaluated which included 64 males and 12 females. Most of the cases came under the VIRADS-II category (23, 30.26%) followed by VIRADS-V (17, 22.36%). VIRADS-I was reported in 14 cases (18.42%). A total of 8 cases (10.52 %) were reported as VIRADS III and 14 cases (18.42%) as VIRADS IV. VIRADS-III was taken as cut off and found to have a sensitivity of 94.44%, a specificity of 87.50%, a positive predictive value of 87.17% and a negative predictive value of 94.59%. Though number of cases are still less to accurately predict test characteristics of VIRADS, our results are consistent with previously done retrospective studies and VIRADS has got good correlation with pathological staging.

Seeing is Believing: State of the Art Imaging of Bladder Cancer

Imaging plays an important role in bladder cancer (BCa) diagnostic work-up. Ultrasound achieves an intermediate sensitivity in detecting urinary tract alterations and is considered a suboptimal imaging technique in diagnosis of BCa. CT urography accurately detects BCa in patients presenting with hematuria Multiparametric MRI achieves a very high rate of BCa detection and helps with accurate staging of patients; however, this modality is still not widely supported by international guidelines. The main applications of MRI are local tumor staging and differentiation between non-muscle-invasive BCa and muscle-invasive BCa. These applications led to development of Vesical Imaging-Reporting and Data System (VI-RADS) scoring system. The VI-RADS scoring system was developed in the setting of post-resection of primary bladder tumor and instillation of intravesical Bacillus Calmette-Guerin therapy; however validation of this system in the post-treatment setting showed promising results. The high risk of BCa recurrence leads to its application in the assessment of response to therapy and for disease surveillance after treatment. MRI is rapidly becoming a leading imaging modality in BCa diagnostic workup, assessment of response to therapies and for longitudinal surveillance, and plays an important role in BCa surgical and radiation therapy treatment planning.

Clinical utility of vesical imaging-reporting and data system (VI-RADS) in non-muscle invasive bladder cancer (NMIBC) patients candidate for en-bloc transurethral resection: A prospective study

OBJECTIVES

To assess accuracy of vesical imaging-reporting and data system (VI-RADS) 5-point score in detection of muscle invasive bladder cancer and avoiding second look transurethral resection of the tumors (TURBT). Additionally, to assess safety and efficacy of bipolar en-block transurethral urethral resection of bladder tumor.

METHODS

Patients with bladder mass up to 5 cm were included in the study. VI-RADS 5-point score was done preoperative for all cases and postoperatively before second look TURBT. Patients were followed up for 12 months.

RESULTS

In all, 80 cases were eligible for the study. Preoperative VI-RADS score at cutoff of 3 had sensitivity of 89.3 %, specificity 83.3 %, postive predective value (PPV) 92.6 %, negative predictive value (NPV) 76.9 %, accuracy of 87.5 %, while at cutoff 2 sensitivity was 82.1%, specificity 91.7%, PPV 95.8%, NPV 68.8%, accuracy of 85.0%. Operative time 28.8 ± 9.4 minutes, hemoglobin drop 0.3 ± 0.05 g/dl, catheterization time 2.8 ± 0.8 days, hospital stay 1.4 ± 0.4 days. No complications occurred. Recurrence in field of resection 3.75%. Detrusor muscle was available in 76 cases (95%). Postoperative VI-RADS score at cutoff of 3 had sensitivity of 78.6%, specificity 77.8%, PPV 84.6%, NPV 70.0%, accuracy of 78.3%. At cutoff 2 VI-RADS score sensitivity was 71.4%, specificity 77.8%, PPV 83.3%, NPV 63.6%, accuracy of 73.9%.

CONCLUSION

VI-RADS 5-point score showed high sensitivity and specificity in preoperative discrimination of non-muscle invasive bladder cancer (NMIBC) from muscle invasive bladder cancer cases and in avoiding unnecessary second look TURBT. Bipolar en-block TURBT technique is both safe and efficacious in resecting NMIBC cases with low recurrence rate.

A novel pathway to detect muscle-invasive bladder cancer based on integrated clinical features and VI-RADS score on MRI: results of a prospective multicenter study

PURPOSE

To determine the clinical, pathological, and radiological features, including the Vesical Imaging-Reporting and Data System (VI-RADS) score, independently correlating with muscle-invasive bladder cancer (BCa), in a multicentric national setting.

METHOD AND MATERIALS

Patients with BCa suspicion were offered magnetic resonance imaging (MRI) before trans-urethral resection of bladder tumor (TURBT). According to VI-RADS, a cutoff of ≥ 3 or ≥ 4 was assumed to define muscle-invasive bladder cancer (MIBC). Trans-urethral resection of the tumor (TURBT) and/or cystectomy reports were compared with preoperative VI-RADS scores to assess accuracy of MRI for discriminating between non-muscle-invasive versus MIBC. Performance was assessed by ROC curve analysis. Two univariable and multivariable logistic regression models were implemented including clinical, pathological, radiological data, and VI-RADS categories to determine the variables with an independent effect on MIBC.

RESULTS

A final cohort of 139 patients was enrolled (median age 70 [IQR: 64, 76.5]). MRI showed sensitivity, specificity, PPV, NPV, and accuracy for MIBC diagnosis ranging from 83-93%, 80-92%, 67-81%, 93-96%, and 84-89% for the more experienced readers. The area under the curve (AUC) was 0.95 (0.91-0.99). In the multivariable logistic regression model, the VI-RADS score, using both a cutoff of 3 and 4 (P < .0001), hematuria (P = .007), tumor size (P = .013), and concomitant hydronephrosis (P = .027) were the variables correlating with a bladder cancer staged as ≥ T2. The inter-reader agreement was substantial (k = 0.814).

CONCLUSIONS

VI-RADS assessment scoring proved to be an independent predictor of muscle-invasiveness, which might implicate a shift toward a more aggressive selection approach of patients' at high risk of MIBC, according to a novel proposed predictive pathway.

Comparison of reduced field-of-view DWI and full field-of view DWI for the differentiation between non-muscle invasive bladder cancer and muscle invasive bladder cancer using VI-RADS

Purpose

To evaluate whether reduced field-of-view (rFOV) DWI sequence improves the differentiation between non-muscle-invasive bladder cancer (NMIBC) and muscle-invasive bladder cancer (MIBC) using VI-RADS.

Material and methods

Eighty-nine patients underwent bladder MRI with full field-of-view (fFOV) DWI and rFOV DWI sequence. Images were independently evaluated by 2 radiologists. The sensitivities, specificities, accuracies, and areas under the curve (AUCs) for the differentiation between NMIBC and MIBC with fFOV DWI and with rFOV DWI sequence were calculated using VI-RADS. Apparent diffusion coefficients (ADC) values were measured for each patient and averaged.

Results

The sensitivity, specificity, accuracy, and AUC by reader 1 were 92%, 78%, 82% and 0.905 with fFOV DWI, and 92%, 86%, 88% and 0.916 with rFOV DWI sequence, respectively. The sensitivity, specificity, accuracy and AUC by reader 2 were 96%, 76%, 82% and 0.900 with conventional DWI, and 96%, 81%, 85% and 0.907 with rFOV DWI sequence, respectively. The specificity and accuracy of reader 1 were significantly better with rFOV DWI sequence than with fFOV DWI, in contrast there was no significant difference for the others. The average of ADC values of fFOV DWI and rFOV DWI sequence were 1.004×10⁻⁶ mm²/s and 1.003×10⁻⁶ mm²/s, respectively.

Conclusion

The diagnostic ability of rFOV DWI sequence may be better than that of fFOV DWI using VI-RADS for the differentiation between NMIBC and MIBC regardless of image-reading experience, it is controversial.

VI-RADS score system - A primer for urologists

Bladder cancer (BCa) is one of the most common cancers worldwide and is also considered to be one of the most relapsing and aggressive neoplasms. About 30% of patients will present with muscle invasive disease, which is associated with a higher risk for metastatic disease. The aim of this article is to review the state of art imaging in Radiology, while providing a complete guide to urologists, with case examples, for the rationale of the development of the Vesical Imaging Reporting and Data System (VI-RADS), a scoring system emphasizing a standardized approach to multiparametric Magnetic Resonance Imaging (mpMRI) acquisition, interpretation, and reporting for BCa. Also, we examine relevant external validation studies and the consolidated literature of mpMRI for bladder cancer. In addition, this article discusses some of the potential clinical implications of this scoring system for disease management and follow-up.

What is the impact of dynamic contrast-enhancement sequence in the Vesical Imaging, Reporting and Data System (VI-RADS)? A subgroup analysis

Background

A scoring system focusing on the risk of muscle layer invasion by Bladder cancer (BCa) has been released, Vesical Imaging - Radiological and Data System (VI-RADS), with a growing interest in evaluating its diagnostic accuracy.

Our goal was to assess the accuracy and reproducibility of the VI-RADS score for assessment of the vesical muscular layer with (multiparametric-mp) and without (biparametric-bp) a dynamic-contrast enhancement (DCE) sequence.

Methods

Retrospective study conducted from July 2018 to July 2020. All patients had suspicions of BCa and underwent Magnetic Resonance Imaging (MRI) before any intervention. MRI was interpreted by two radiologists with different levels of experience, and a VI-RADS score assigned in two different sessions (3 months apart) without and with DCE. After exclusions, 44 patients with 50 lesions were enrolled. The standard of reference was transurethral resection in 18 patients (40.9%) and cystectomy in 26 patients (59.1%).

Results

Twenty-five lesions (50%) were muscle-invasive. There was no significant difference between the two groups for gender and presence of a stalk, but mean age of NMIBCa group was significantly higher (p = 0.01). The sizes of lesions were significantly different between groups for both readers at 2.42+/− 1.58 vs. 5.70+/− 2.67 cm for reader 1 (p < 0.0001) and 2.37+/− 1.50 vs. 5.44 +/− 2.90 cm for reader 2 (p = 0.001). The area under the curve (AUC) for muscle invasion with mpVI-RADS, considering all lesions, was 0.885 +/− 0.04 (95% CI-0.79-0.98) for reader 1 and 0.924 +/− 0.04 (0.84–0.99) for reader 2, and for bpVI-RADS was 0.879+/− 0.05 and 0.916 +/− 0.04 (0.85–0.99), respectively, both differences not statistically significant (p = 0.24 and 0.07, respectively). When considering only small lesions (< 3.0 cm), the accuracy for mpVI-RADS was 0.795 +/− 0.11 (0.57–1.0) for reader1, and 0.80 +/− 0.11(0.57–1.0) for reader 2, a non-significant difference (p = 0.56) and for bpVI-RADS was 0.747 +/− 0.12 (0.50–0.99) for reader 1 and 0.80 +/− 0.11(0.57–1.0) for reader 2, a significant difference (p = 0.04). The intraclass correlation coefficient for the final score was 0.81 (0.60–1.0) for mpVI-RADS and 0.85 (0.63–1.0) for bpVI-RADS.

Conclusion

The VI-RADS system was accurate in demonstrating muscle-invasive BCa, for both experienced and less experienced reader, regardless of the use of a DCE sequence. However, when only small lesions were assessed the difference between the two readers was significant only for the biparametric analysis. The reproducibility was similar between multiparametric and biparametric approach.

Biparametric magnetic resonance imaging assessment for detection of muscle-invasive bladder cancer: a systematic review and meta-analysis

OBJECTIVES

To investigate if removing DCE from the Vesical Imaging Reporting and Data System (VI-RADS) influences the diagnostic accuracy of muscle-invasive bladder cancer (MIBC). We also explored using different reference standards on the MRI diagnostic performance.

METHODS

We searched the Cochrane Library, Embase, and PubMed databases to June 26, 2021. Pooled biparametric MRI (bpMRI, T2WI+DWI) and multiparametric MRI (mpMRI, T2WI+DWI+DCE) sensitivities and specificities and the diagnostic performances of these methods for MIBC were compared using different reference standards.

RESULTS

Seventeen studies with 2344 patients were finally included, of which 7 studies, including 1041 patients, reported the diagnostic performance of bpMRI. VI-RADS showed sensitivities and specificities of 0.91 (95% CI 0.87-0.94) and 0.86 (95% CI 0.77-0.91) at cutoff scores of 3, and 0.85 (95% CI 0.77-0.90) and 0.93 (95% CI 0.89-0.96) at cutoff scores of 4. BpMRI showed sensitivities and specificities of 0.90 (95% CI 0.69-0.97) and 0.90 (95% CI 0.81-0.95), and 0.84 (95% CI 0.78-0.88) and 0.97 (95% CI 0.87-0.99), respectively, for cutoff scores of 3 and 4. The sensitivities of bpMRI vs mpMRI for MIBC were not significantly different, but bpMRI was more specific than mpMRI at cutoff scores of 3 (p = 0.02) and 4 (p = 0.02). The VI-RADS studies using primary transurethral resection of bladder tumors (TURBT) as the reference standard had significantly higher sensitivities (p < 0.001) than those using secondary TURBT or radical cystectomy as the reference.

DATA CONCLUSION

BpMRI and conventional VI-RADS had similar diagnostic efficacies for MIBC. Since MRI overestimated MIBC diagnoses using primary TURBT as the reference standard, we recommend using secondary TURBT as the reference standard.

KEY POINTS

• Biparametric MRI without DCE had similar diagnostic efficacies for MIBC compared with conventional VI-RADS. • The sensitivity of VI-RADS was overestimated when referring to the primary TURBT results. • Biparametric MRI comprised of T2WI and DWI could be used for detecting MIBC in clinical practice.

Diagnostic accuracy of vesical imaging-reporting and data system (VI-RADS) for the detection of muscle-invasive bladder cancer: a meta-analysis

PURPOSE

Vesical Imaging-Reporting and Data System (VI-RADS) was proposed and considered as a standardized reporting criterion for bladder magnetic resonance imaging (MRI). VI-RADS could suggest the likelihood of muscle invasion based on the multiparametric MRI (mp-MRI) findings which contain five-point scores. The current study is designed to comprehensively and systematically evaluate the diagnostic performance of VI-RADS (score 3 and 4) for predicting muscle invasion.

METHODS

The Cochrane Library, Embase, and PubMed were searched comprehensively from inception to October 2021.

RESULTS

Finally, 19 studies incorporating 2900 patients were enrolled. The pooled sensitivity and specificity of VI-RADS 3 for predicting muscle invasion were 0.92 (95%CI 0.89-0.94) and 0.82 (95%CI 0.76-0.87), respectively. The pooled sensitivity and specificity of VI-RADS 4 were 0.78 (95%CI 0.72-0.83) and 0.96 (95%CI 0.93-0.97), respectively. And the area under the curve (AUCs) of VI-RADS 3 and 4 were all 0.94 (95%CI 0.92-0.96). No significant publication biases were not observed for VI-RADS 3 (P = 0.74) and 4 (P = 0.57).

CONCLUSION

The VI-RADS reveals a good diagnostic performance for predicting muscle invasive in bladder cancer, which also has good clinical utilities and applicability. And VI-RADS 3 and 4 as cutoff values provide similar overall diagnostic and could be selectively applied individually. Prospective studies with a large scale are further required to validate the accuracy of the VI-RADS score.

The accuracy of Vesical Imaging-Reporting and Data System (VI-RADS): an updated comprehensive multi-institutional, multi-readers systematic review and meta-analysis from diagnostic evidence into future clinical recommendations

Purpose

To determine through a comprehensive systematic review and meta-analysis the cumulative diagnostic performance of vesical imaging-reporting and data system (VIRADS) to predict preoperative muscle-invasiveness among different institutions, readers, and optimal scoring accuracy thresholds.

Methods

PubMed, Cochrane and Embase were searched from inception up to May 2021. Sensitivity (Sn), Specificity (Sp) were first estimated and subsequently pooled using hierarchical summary receiver operating characteristics (HSROC) modeling for both cut-off ≥ 3 and ≥ 4 to predict muscle-invasive bladder cancer (MIBC). Further sensitivity analysis, subgroup analysis and meta-regression were conducted to investigate contribution of moderators to heterogeneity.

Results

In total, n = 20 studies from 2019 to 2021 with n = 2477 patients by n = 53 genitourinary radiologists met the inclusion criteria. Pooled weighted Sn and Sp were 0.87 (95% CI 0.82–0.91) and 0.86 (95% CI 0.80–0.90) for cut-off ≥ 3 while 0.78 (95% CI 0.74–0.81) and 0.94 (95% CI 0.91–0.96) for cut-off ≥ 4. The area under the HSROC curve was 0.93 (95% CI 0.90–0.95) and 0.91 (95% CI 0.88–0.93) for cut-off ≥ 3 and ≥ 4, respectively. Meta-regression analyses showed no influence of clinical characteristics nor cumulative reader’s experience while study design and radiological characteristics were found to influence the estimated outcome.

Conclusion

We demonstrated excellent worldwide diagnostic performance of VI-RADS to determine pre-trans urethral resection of bladder tumor (TURBT) staging. Our findings corroborate wide reliability of VI-RADS accuracy also between different centers with varying experience underling the importance that standardization and reproducibility of VI-RADS may confer to multiparametric magnetic resonance imaging (mpMRI) for preoperative BCa discrimination.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00345-022-03969-6.

Accuracy of Inchworm Sign on Diffusion-Weighted MRI in Differentiating Muscle-Invasive Bladder Cancer

BACKGROUND

Inchworm sign is a finding on diffusion-weighted magnetic resonance imaging (DWI-MRI) and is used to better stratify T-staging in muscle invasive (MIBC) and non-muscle-invasive bladder cancer (NMIBC). An uninterrupted low submucosal signal on DWI, defined as inchworm sign (IS), indicates NMIBC.

OBJECTIVE

We aimed to define the diagnostic accuracy of IS in primary bladder cancer, as well as find agreement between the urologists and the radiologist.

METHODS

Between December 2018 and December 2020, we retrospectively analyzed 95 primary bladder cancer patients who had undergone multiparametric-MRI before transurethral resection. Patients with former bladder cancer history, tumors smaller than 10 mm, and MRI without proper protocol, as well as patients who did not attend follow-up, were excluded. In total, 71 patients' images were evaluated by a genitourinary specialist radiologist and two urologists. Sensitivity, specificity, positive and negative predictive values of IS and VI-RADS in differentiating MIBC and NMIBC, and interreader agreement between the radiologist and urologists were analyzed.

RESULTS

During follow-up, 38 patients (53.5%) were IS-positive, while 33 patients (46.5%) were negative. Among the 33 patients with negative IS, 14 patients (42.4%) had MIBC. Meanwhile, two out of the 38 IS-positive patients (5.3%) had MIBC (p = 0.00). Sensitivity, specificity, and positive and negative predictive values of IS in predicting MIBC were 87.5%, 63.6%, 41.2%and 94.6%, respectively. The interobserver agreement between the urologists and radiologist was almost perfect ( K  = 0.802 and K  = 0.745).

CONCLUSION

The absence of IS on DWI is useful in differentiating MIBC from NMIBC. It is a simple finding that can be interpreted by urologists.

Accuracy and Challenges in the Vesical Imaging-Reporting and Data System for Staging Bladder Cancer

BACKGROUND

The Vesical Imaging-Reporting and Data System (VI-RADS) scoring system has been widely used to stage bladder cancer (BCa) since 2018.

PURPOSE

To describe the characteristics of cases with discordant T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI) scores in patients with BCa and further verify the accuracy of the VI-RADS scoring system and the necessity of dynamic contrast-enhanced (DCE) sequence.

STUDY TYPE

Retrospective.

SUBJECTS

A total of 106 patients (include 16.5% female) with bladder cancer.

SEQUENCE

T2WI (fast spin echo), DWI (echo planer imaging), and DCE (gradient echo).

ASSESSMENT

Some cases are difficult to score according to the system, mainly when the T2WI (category 4) and DWI (category 2) sequence scores are discordant, termed the discordant group below. The complementary group will be termed concordant group. Each MRI sequence was reviewed respectively according to the 5-point VI-RADS scoring system by three observers. The diagnostic ability of sequences for evaluating muscle invasion by BCa was calculated using histopathology as the reference standards.

STATISTICAL TESTS

Receiver operating characteristic (ROC) curve, DeLong test, intraclass correlation coefficient. A P value of 0.05 or less was considered statistically significant.

RESULTS

Fourteen cases (13.2%) had discordant VI-RADS scoring system. In the discordant group, the area under the ROC curve (AUC) of DCE was 0.875, while the T2WI and DWI showed limited diagnostic performance (AUCs = 0.50). In the concordant group, there was no significant difference in diagnostic efficacy between the overall VI-RADS (AUC: 0.950) and the combination of T2WI and DWI (AUC: 0.946) (P = 0.56). Among all patients, the AUC of overall VIRADS was 0.939 with a 3 or greater cutoff value.

DATA CONCLUSION

The DCE was crucial in the discordant group for evaluating muscle-invasiveness, while DCE may not be necessary for the concordant group. The VI-RADS scoring system performed with overall good diagnostic performance in evaluating muscle-invasiveness in BCa patients.

EVIDENCE LEVEL

4 TECHNICAL EFFICACY: Stage 3.

Clinical validity of non-contrast-enhanced VI-RADS: prospective study using 3-T MRI with high-gradient magnetic field

OBJECTIVES

To develop a modified Vesical Imaging Reporting and Data System (VI-RADS) without dynamic contrast-enhanced imaging (DCEI), termed "non-contrast-enhanced VI-RADS (NCE-VI-RADS)", and to assess the additive impact of denoising deep learning reconstruction (dDLR) on NCE-VI-RADS.

METHODS

From January 2019 through December 2020, 163 participants who underwent high-gradient 3-T MRI of the bladder were prospectively enrolled. In total, 108 participants with pathologically confirmed bladder cancer by transurethral resection were analyzed. Tumors were evaluated based on VI-RADS (scores 1-5) by two readers independently: an experienced radiologist (reader 1) and a senior radiology resident (reader 2). Conventional VI-RADS assessment included all three imaging types (T2-weighted imaging [T2WI], diffusion-weighted imaging [DWI], and dynamic contrast-enhanced imaging [DCEI]). Also evaluated were NCE-VI-RADS comprising only non-contrast-enhanced imaging types (T2WI and DWI), and "NCE-VI-RADS with dDLR" comprising T2WI processed with dDLR and DWI. All systems were assessed using receiver-operating characteristic curve analysis and simple and/or weighted κ statistics.

RESULTS

Muscle invasion was identified in 23/108 participants (21%). Area under the curve (AUC) values for diagnosing muscle invasion were as follows: conventional VI-RADS, 0.94 and 0.91; NCE-VI-RADS, 0.93 and 0.91; and "NCE-VI-RADS with dDLR", 0.96 and 0.93, for readers 1 and 2, respectively. Simple κ statistics indicated substantial agreement for NCE-VI-RADS and almost perfect agreement for conventional VI-RADS and "NCE-VI-RADS with dDLR" between the two readers.

CONCLUSION

NCE-VI-RADS achieved predictive accuracy for muscle invasion comparable to that of conventional VI-RADS. Additional use of dDLR improved the diagnostic accuracy of NCE-VI-RADS.

KEY POINTS

• Non-contrast-enhanced Vesical Imaging Reporting and Data System (NCE-VI-RADS) was developed to avoid risk related to gadolinium-based contrast agent administration. • NCE-VI-RADS had predictive accuracy for muscle invasion comparable to that of conventional VI-RADS. • The additional use of denoising deep learning reconstruction (dDLR) might further improve the diagnostic accuracy of NCE-VI-RADS.

Role of Vesical Imaging-Reporting and Data System in predicting muscle-invasive bladder cancer: A diagnostic meta-analysis

The objective of this study is to systematically evaluate the diagnostic performance of the Vesical Imaging-Reporting and Data System for predicting muscle-invasive bladder cancer. Embase, PubMed and Web of Science were systematically searched from 1 September 2018 to 30 July 2021 to include proper studies. We included studies that included data on Vesical Imaging-Reporting and Data System and their associated pathological findings, and we assessed their quality using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. The pooled sensitivity and specificity were calculated and plotted using hierarchical summary receiver operating characterisijutic modeling. Meta-regression analysis was carried out to detect heterogeneity. A total of 20 studies with 2725 patients were included. When the cut-off point was 3, the pooled sensitivity and specificity were 0.92 (0.89-0.94) and 0.85 (0.78-0.90), respectively, and 0.82 (0.75-0.88) and 0.95 (0.91-0.97), respectively, when the cut-off point was 4. The area under the curve was 0.95 and 0.95, respectively. Heterogeneity was substantially considerable in sensitivity and specificity. All subgroup variables, including patient number, study design, magnetic resonance imaging field strength, number of radiologists, surgery pattern, diffusion-weighted imaging, and dynamic contrast-enhanced magnetic resonance imaging, contributed to sensitivity heterogeneity when the cut-off point was 3 and specificity heterogeneity when the cut-off point was 4. Multiple image acquisition plane of diffusion-weighted imaging achieved a higher sensitivity than single image acquisition plane of diffusion-weighted imaging in both the Vesical Imaging-Reporting and Data System 3 and 4 groups, and higher specificity in the Vesical Imaging-Reporting and Data System 4 group. Another significant source of heterogeneity was the cut-off point. The diagnostic performance of the Vesical Imaging-Reporting and Data System for predicting muscle-invasive bladder cancer was excellent in both cut-off points of the Vesical Imaging-Reporting and Data System 3 and 4. Multiple image acquisition planes of diffusion-weighted imaging should be given more attention in the Vesical Imaging-Reporting and Data System.

Diagnostic accuracy of vesical imaging-reporting and data system (VI-RADS) in suspected muscle invasive bladder cancer: A systematic review and diagnostic meta-analysis

OBJECTIVE

To investigate the accuracy of Vesical Imaging-Reporting and Data System (VI-RADS) in detection of muscle-invasive bladder cancer (MIBC) we performed a systematic review and meta-analysis of the available literature.

MATERIALS AND METHODS

Scopus, Web of Science, PubMed, and EMBASE were searched up to 8 March 2021 for the studies evaluating the diagnostic performance of VI-RADS for the detection of MIBC. Inclusion criteria were patients with bladder cancer; index test of VI-RADS based on multiparametric MRI; reference test of histopathological findings from TURBT, re-TURBT, or cystectomy and study design of cohort. Case reports, review articles, and editorials were eliminated, as well as studies with insufficient knowledge to acquire TP, FP, FN, and TN values of VI-RADS. The MIDAS module of STATA was for statistical analysis. The heterogeneity was explored using subgroup analysis and meta-regression analysis.

RESULTS

Overall, 22 eligible studies, consisting of 2,576 participants and 5,414 MRI reports, were included in this meta-analysis. The area under curve (AUC) of VI-RADS at cut-point values of 3 and 4 were 0.93 (95%CI: 0.91, 0.95), 0.93 (95%CI: 0.90, 0.95), respectively. Based on Youden's J statistic, the optimal VI-RADS cutoff value for predicting MIBC was determined as 3 which granted a pooled sensitivity of 89% (95%CI: 87%, 91%; I²=48%) and a specificity of 84% (95%CI: 80%, 87%; I²=90%). Based on meta-regression, the sources of inter-study heterogeneity for VI-RADS ≥ 3 were the sample size > 70, study design, single-center vs multi-center, patient population characteristics (i.e., gender, age), reference standard, histology, magnetic strength, T2WI slice thickness, and the number of radiologists reporting the MRI results (P value ≤ 0.01).

CONCLUSION

The VI-RADS demonstrates consistently high diagnostic accuracy to predict MIBC. This scoring system could be applied in standard staging MRI reports of bladder cancer and can be incorporated into future MIBC work up guidelines.

Accuracy of the Vesical Imaging-Reporting and Data System (VIRADS) for pre-treatment staging of bladder cancer in an Australian cohort

INTRODUCTION

To evaluate the performance of the Vesical Imaging-Reporting and Data System (VIRADS) in differentiating muscle-invasive and non-muscle-invasive bladder cancer and whether this reporting system improves inter-reader agreement.

METHODS

Sixty-four cases of multiparametric 3 tesla bladder MRI from January 2014 to May 2020 were reviewed retrospectively. T2-weighted, diffusion and post-contrast images were reviewed. All magnetic resonance images were reported by a radiologist with 15 years' experience (Reader 1) and a final year radiology trainee with a special interest in urogenital imaging with 3 years of experience (Reader 2). Both readers were blinded to clinical history and histopathology results when scoring each lesion.

RESULTS

The sensitivity and specificity for differentiating MIBC and NMIBC were 91% and 68%, respectively, for Reader 1 and 91% and 63%, respectively, for Reader 2. The inter-reader agreement for assigning VIRADS scores was 0.79. The area under the receiver operator curve for Reader 1 and 2 were not significantly different (Reader 1 = 0.79, Reader 2 = 0.77, P = 0.83).

CONCLUSIONS

Staging of bladder cancer prior to treatment can be accurately and reliably diagnosed using VIRADS, a novel, standardised reporting system for bladder MRI.

Visual MRI T-category versus VI-RADS evaluation from multiparametric MRI in the detection of muscle-invasion in patients with suspected bladder cancer: single centre registered clinical trial (MIB-trial)

BACKGROUND

Multiparametric Magnetic Resonance Imaging (mpMRI) has been proposed to add value in the diagnostic pathway of bladder cancer (BC). We wanted to evaluate the performance of mpMRI for muscle-invasion detection in BC patients using a subjective MRI visual T-category and the Vesical Imaging-Reporting and Data System (VI-RADS) score.

METHODS

This single centre clinical trial included 45 patients with suspected BC (ClinicalTrials.gov Identifier: NCT02662166). All patients had mpMRI prior to transurethral resection of bladder tumour (TUR-BT). The imaging was correlated to histopathological findings. Two individual radiologists evaluated all the mpMRI images. A binary cut-off point for the detection of muscle-invasion in the MRI visual T-category was defined between T1 and T2 and the VI-RADS cut-off score was 3. Cohen's Kappa values were used to evaluate the agreement between the two radiologists. Sensitivity, Specificity, Area Under Receiver Operator Characteristics Curve (AUC), Positive Predictive Value (PPV) and Negative Predictive Value (NPV) were calculated to evaluate the performance of both radiologists separately.

RESULTS

AUC values for reader A and B using the MRI visual T-category were 0.76 and 0.56, while the corresponding values for VI-RADS were 0.63 and 0.57, respectively. There was no statistically significant difference between the radiologists nor the reporting systems (p > .05) in the detection of muscle-invasion. The inter-reader agreement was substantial (0.61-0.80).

CONCLUSION

Both the subjective MRI visual T-category and VI-RADS score had only a low to moderate accuracy for the detection of muscle-invasion in BC with no statistically significant difference between the reporting systems.

Vesical Imaging Reporting and Data System (VI-RADS): Are the individual MRI sequences equivalent in diagnostic performance of high grade NMIBC and MIBC?

PURPOSE

To investigate the diagnostic performance of the overall Vesical Imaging Reporting and Data System (VI-RADS) score and its individual magnetic resonance imaging (MRI) parameters in assessing grade and muscle invasiveness of bladder cancer (BC).

METHODS

This IRB-approved retrospective, single-center, cross-sectional study included patients with BC wo underwent 3 Tesla preoperative multiparametric (mp)-MRI including T2-weighted (T2w), diffusion weighted imaging (DWI) and dynamic contrast enhanced (DCE) sequences. An independent evaluation according to VI-RADS was performed by two radiologists in separate sessions, blinded to histological findings.

RESULTS

The mean age of 59 included patients was 68.2 (±13.6 standard deviation) years. Among bladder cancer patients, 26 (51%) were identified as high grade and 14 (27.5%) as muscle invasive urothelial carcinomas in histological sections. The area under the curve (AUC) for the overall VI-RADS score to predict muscle invasion was 0.986 (R1) and 0.992 (R2). The AUC to diagnose high grade bladder cancer was 0.908 (R1) and 0.905 (R2). There was no significance difference between the AUC of single parameters (T2w, DWI and DCE) compared to the total VI-RADS score (P > 0.05, respectively). Upon multivariate logistic regression, only the T2w VI-RADS score contributed independently to the diagnosis of high grade and muscle invasive bladder cancer (P = 0.001 (R1) and P = 0.0022 (R2) for high grade cancer; P = 0.0007 (R1) and P = 0.0019 (R2) for muscle invasiveness).

CONCLUSION

VI-RADS provides high diagnostic accuracy to diagnose high grade and muscle invasive BC. Our results suggest, that mp-MRI parameters provide overlapping information and for sake of clinical simplicity, a biparametric, contrast free image acquisition may be approached without sacrificing diagnostic accuracy.

[French ccAFU guidelines - update 2020-2022: bladder cancer]

OBJECTIVE

- To update French guidelines for the management of bladder cancer specifically non-muscle invasive (NMIBC) and muscle-invasive bladder cancers (MIBC).

METHODS

- A Medline search was achieved between 2018 and 2020, notably regarding diagnosis, options of treatment and follow-up of bladder cancer, to evaluate different references with levels of evidence.

RESULTS

- Diagnosis of NMIBC (Ta, T1, CIS) is based on a complete deep resection of the tumor. The use of fluorescence and a second-look indication are essential to improve initial diagnosis. Risks of both recurrence and progression can be estimated using the EORTC score. A stratification of patients into low, intermediate and high risk groups is pivotal for recommending adjuvant treatment: instillation of chemotherapy (immediate post-operative, standard schedule) or intravesical BCG (standard schedule and maintenance). Cystectomy is recommended in BCG-refractory patients. Extension evaluation of MIBC is based on contrast-enhanced pelvic-abdominal and thoracic CT-scan. Multiparametric MRI can be an alternative. Cystectomy associated with extended lymph nodes dissection is considered the gold standard for non-metastatic MIBC. It should be preceded by cisplatin-based neoadjuvant chemotherapy in eligible patients. An orthotopic bladder substitution should be proposed to both male and female patients with no contraindication and in cases of negative frozen urethral samples; otherwise transileal ureterostomy is recommended as urinary diversion. All patients should be included in an Early Recovery After Surgery (ERAS) protocol. For metastatic MIBC, first-line chemotherapy using platin is recommended (GC or MVAC), when performans status (PS <1) and renal function (creatinine clearance >60 mL/min) allow it (only in 50% of cases). In second line treatment, immunotherapy with pembrolizumab demonstrated a significant improvement in overall survival.

CONCLUSION

- These updated French guidelines will contribute to increase the level of urological care for the diagnosis and treatment of patients diagnosed with NMIBC and MIBC.

Validation of vesical imaging reporting and data system score for the diagnosis of muscle invasive bladder cancer: A prospective cross-sectional study

Objective

Vesical Imaging Reporting and Data System (VIRADS) score was developed to standardize the reporting and staging of bladder tumors on pre-operative multiparametric magnetic resonance imaging. It helps in avoiding unnecessary repeat transurethral resection of bladder tumor in high-risk non-muscle-invasive bladder cancer patients. This study was done to determine the validity of VIRADS score prospectively for the diagnosis of muscle-invasive bladder cancer.

Methods

This study was conducted from March 2019 to March 2020 at Sawai Man Singh Medical College and Hospital, Jaipur, Rajasthan, India. Patients admitted with the provisional diagnosis of bladder tumor were included as participants. All these patients underwent a 3 Tesla mpMRI to obtain a VIRADS score before they underwent transurethral resection of bladder tumor and these data were analyzed to evaluate the correlation of pre-operative VIRADS score with muscle invasiveness of the tumor in final biopsy report.

Results

A cut-off of VIRADS ≥4 for prediction of detrusor muscle invasion yielded a sensitivity of 79.4%, specificity of 94.2%, positive predictive value of 90.0%, negative predictive value of 87.5%, and diagnostic accuracy of 86.4%. A cut off of VIRADS ≥3 for prediction of detrusor muscle invasion yielded a sensitivity of 91.2%, specificity of 78.8%, positive predictive value of 73.8%, negative predictive value of 93.2%, and accuracy of 83.7%. The receiver operating curve showed the area under the curve to be 0.922 (95% confidence interval: 0.862–0.983).

Conclusion

VIRADS score appears to be an excellent and effective pre-operative radiological tool for the prediction of detrusor muscle invasion in bladder cancer.

Detecting Muscle Invasion of Bladder Cancer Using a Proposed Magnetic Resonance Imaging Strategy

BACKGROUND

Accurate evaluation of the invasion depth of tumors with a Vesical Imaging-Reporting and Data System (VI-RADS) score of 3 is difficult.

PURPOSE

To evaluate the diagnostic performance of a new magnetic resonance imaging (MRI) strategy based on the integration of the VI-RADS and tumor contact length (TCL) for the diagnosis of muscle-invasive bladder cancer (MIBC).

STUDY TYPE

Single center, retrospective.

SUBJECTS

A group of 179 patients with a mean age of 67 years (range, 24.0-96.0) underwent multiparametric MRI (mpMRI) before surgery, including 147 (82.1%) males and 32 (17.9%) females. Twenty-four (13.4%), 90 (50.3%), 43 (24.0%), 15 (8.4%), and 7 (3.9%) cases were Ta, T1, T2, T3, and T4, respectively.

FIELD STRENGTH/SEQUENCE

A 1.5 T and 3.0 T, T2-weighted turbo spin-echo (TSE), single-shot echo-planar (SS-EPI), diffusion-weighted imaging (DWI), and T1-weighted volumetric interpolated breath-hold examination (T1-VIBE).

ASSESSMENT

Three radiologists independently graded the VI-RADS score and measured the TCL on index lesion images. A proposed MRI strategy called VI-RADS_TCL was introduced by modifying the VI-RADS score, which was downgraded to VI-RADS 3F (equal to a VI-RADS score of 2) if VI-RADS = 3 and TCL < 3 cm.

STATISTICAL TESTS

Intraclass correlation coefficients (ICCs), Mann-Whitney U test, chi-square tests, receiver operating characteristic (ROC) curves, and 2 × 2 contingency tables were applied.

RESULTS

Inter-reader agreement values were 0.941 (95% CI, 0.924-0.955) and 0.934 (95% CI, 0.916-0.948) for the TCL and VI-RADS score. The TCL was significantly increased in the MIBC group (6.40-6.85 cm) compared with the NMIBC group (1.98-2.45 cm) (P < 0.05). The specificity and positive predictive values (PPV) of VI-RADS_TCL were 82.46%-87.72% and 90.91%-91.59%, which were significantly greater than VI-RADS score (P < 0.05). Additionally, 52.17%-55.88% NMIBC lesions with VI-RADS 3 were downgraded to 3F by using VI-RADS_TCL.

DATA CONCLUSION

The proposed MRI strategy could reduce the false-positive rate of lesions with a VI-RADS score of 3 while retaining sensitivity.

EVIDENCE LEVEL

4 TECHNICAL EFFICACY: 2.

MR-Guided Adaptive Radiotherapy for Bladder Cancer

Radiotherapy has an important role in the curative and palliative treatment settings for bladder cancer. As a target for radiotherapy the bladder presents a number of technical challenges. These include poor tumor visualization and the variability in bladder size and position both between and during treatment delivery. Evidence favors the use of magnetic resonance imaging (MRI) as an important means of tumor visualization and local staging. The availability of hybrid systems incorporating both MRI scanning capabilities with the linear accelerator (MR-Linac) offers opportunity for in-room and real-time MRI scanning with ability of plan adaption at each fraction while the patient is on the treatment couch. This has a number of potential advantages for bladder cancer patients. In this article, we examine the technical challenges of bladder radiotherapy and explore how magnetic resonance (MR) guided radiotherapy (MRgRT) could be leveraged with the aim of improving bladder cancer patient outcomes. However, before routine clinical implementation robust evidence base to establish whether MRgRT translates into improved patient outcomes should be ascertained.

Multiparametric magnetic resonance imaging for bladder cancer: a comprehensive systematic review of the Vesical Imaging-Reporting and Data System (VI-RADS) performance and potential clinical applications

BACKGROUND

The Vesical Imaging-Reporting and Data System (VI-RADS) score is a novel standardized approach to image and report bladder cancer (BC) with multiparametric MRI (mpMRI).

OBJECTIVES

To describe and evaluate the performance of the VI-RADS score using mpMRI and assess its potential clinical applications and limitations.

METHODS

A systematic review was conducted using the MEDLINE and EMBASE electronic bibliographic databases between June 2020 and December 2020. All reports deemed relevant to describe the VI-RADS score and assess its performance and applications were retrieved. Results presentation stands as narrative, purely descriptive synthesis based on aggregate studies data.

RESULTS

A total of 20 relevant studies were retrieved: three meta-analyses, five prospective studies, and twelve retrospective studies. The retrospective studies covered 1676 patients, while the prospective studies included a total number of 468 patients. Pooled sensitivity, specificity to differentiate muscle-invasive from non-muscle-invasive bladder cancer, ranged from 74.1% to 97.3%, and 77% to 100%, respectively. The chosen VI-RADS score thresholds for this discrimination varied across studies. The interreader agreement ranged from 0.73 to 0.95. Currently, the potential clinical applications of VI-RADS consist of initial BC risk stratification, assessment of neoadjuvant therapies response, and bladder sparing approaches, although further validation is required.

CONCLUSIONS

The VI-RADS score helps to discriminate muscle invasive from non-muscle invasive BC with good performance and reproducibility. A simple algorithm based on four basic questions may enhance its popularization. Further studies are required to validate the clinical applications.

Application of bi-planar reduced field-of-view DWI (rFOV DWI) in the assessment of muscle-invasiveness of bladder cancer

OBJECTIVES

To compare the image quality of the reduced field-of-view (rFOV) diffusion-weighted imaging (DWI) with the full field-of-view (fFOV) DWI in the assessment of bladder cancer (BC); and to explore the possible superiority of bi-planar (axial and sagittal) rFOV DWI over single planar fFOV DWI in predicting muscle-invasiveness of BC.

MATERIALS AND METHODS

This retrospective study analyzed 61 patients with BC who underwent DWI sequences including axial fFOV DWI, axial rFOV DWI, and sagittal rFOV DWI. Qualitative and quantitative image quality assessment were compared between axial fFOV DWI and rFOV DWI sequences. The tumor with its base could be clearly displayed on DWI was defined as the evaluable lesion, and the number of evaluable lesions detected from single axial fFOV DWI, axial rFOV DWI, sagittal rFOV DWI, and bi-planar rFOV DWI sequences was recorded and compared. The apparent diffusion coefficient (ADC) was compared between non-muscular-invasive bladder cancer (NMIBC) and muscular-invasive bladder cancer (MIBC) based on the sequences of axial fFOV DWI and rFOV DWI, respectively. Vesical Imaging-Reporting and Data System (VI-RADS) was introduced to evaluate the overall risk of muscle-invasiveness of BC and receiver operating characteristic (ROC) curve analysis was applied to assess the diagnostic performance.

RESULTS

The contrast-to-noise ratio (CNR) of the rFOV DWI was significantly higher than that of fFOV DWI (p < 0.01), while the signal-to-noise ratio (SNR) was significantly lower than that of fFOV DWI (p < 0.01). The subjective score of rFOV DWI was significantly higher than that of fFOV DWI (p < 0.01). The ADC value of the MIBC group was significantly lower than that of the NMIBC in both rFOV DWI and fFOV DWI (all p < 0.01). The number of evaluable lesions detected from the bi-planar rFOV DWI was significantly higher than that detected from the single axial fFOV DWI, axial rFOV DWI, and sagittal rFOV DWI (all p < 0.01). VI-RADS based on the bi-planar rFOV DWI offered high predictive power (the area under the ROC curve, 0.946) for predicting the presence of muscle-invasiveness of BC.

CONCLUSION

Bi-planar rFOV DWI may provide more diagnostic confidence than the single planar DWI for predicting the presence of muscle-invasiveness in BC, with improved image quality over the fFOV DWI.

Utilization of imaging for staging in bladder cancer: is there a role for MRI or PET-computed tomography?

PURPOSE OF REVIEW

Accurate staging of bladder cancer is essential to guide appropriate management. In this review, we discuss the principles, applications and performance of multiparametric MRI (mpMRI) and PET-computer tomography (PET-CT) for local and distant staging of bladder cancer.

RECENT FINDINGS

Bladder mpMRI has a high diagnostic performance in local staging of bladder cancer, superior to other imaging modalities. It can accurately differentiate muscle invasive bladder cancer (MIBC) from non-MIBC (NMIBC), as well as ≤T2 from ≥T3 stages. mpMRI can be used to assess pelvic lymph nodes, although its sensitivity is relatively low. For the assessment of the upper urinary tract, CT urography is the imaging modality of choice. magnetic resonance urography is a viable alternative to CT in selected cases. Although PET-CT is accurate for nodal and distant staging of bladder cancer, there is no clear evidence on its superior diagnostic performance compared with contrast-enhanced CT.

SUMMARY

mpMRI is the most accurate imaging modality for local staging of bladder cancer, capable to accurately distinguish MIBC from NMIBC. Nodal and distant staging relies primarily on contrast-enhanced CT.

VI-RADS for Bladder Cancer: Current Applications and Future Developments

Bladder cancer (BCa) is among the ten most frequent cancers globally. It is the tumor with the highest lifetime treatment-associated costs, and among the tumors with the heaviest impacts on postoperative quality of life. The purpose of this article is to review the current applications and future perspectives of the Vesical Imaging Reporting and Data System (VI-RADS). VI-RADS is a newly developed scoring system aimed at standardization of MRI acquisition, interpretation, and reporting for BCa. An insight will be given on the BCa natural history, current MRI applications for local BCa staging with assessment of muscle invasiveness, and clinical implications of the score for disease management. Future applications include risk stratification of nonmuscle invasive BCa, surveillance, and prediction and monitoring of therapy response. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY STAGE: 2.

The Role of Imaging in Bladder Cancer Diagnosis and Staging

Bladder cancer (BC) is the most common cancer of the urinary tract in the United States. Imaging plays a significant role in the management of patients with BC, including the locoregional staging and evaluation for distant metastatic disease, which cannot be assessed at the time of cystoscopy and biopsy/resection. We aim to review the current role of cross-sectional and molecular imaging modalities for the staging and restaging of BC and the potential advantages and limitations of each imaging modality. CT is the most widely available and frequently utilized imaging modality for BC and demonstrates good performance for the detection of nodal and visceral metastatic disease. MRI offers potential value for the locoregional staging and evaluation of muscular invasion of BC, which is critically important for prognostication and treatment decision-making. FDG-PET/MRI is a novel hybrid imaging modality combining the advantages of both MRI and FDG-PET/CT in a single-setting comprehensive staging examination and may represent the future of BC imaging evaluation.

Quantitation of bladder cancer for the prediction of muscle layer invasion as a complement to the vesical imaging-reporting and data system

OBJECTIVES

To examine the diagnostic performance of Vesical Imaging-Reporting and Data System (VIRADS) and to find a quantitative indicator for predicting muscle layer invasion of bladder cancer.

METHODS

3-T MRI of 82 patients performed before transurethral resection of bladder tumors or radical cystectomy between July 2018 and June 2019 were retrospectively analyzed. For one index lesion of each patient, two radiologists independently assigned VIRADS score and measured tumor-wall interface (contact length between tumor and bladder wall) on T2-weighted, diffusion-weighted, and dynamic contrast-enhanced MRI. Inter-reader agreement was assessed, and logistic regression analysis was performed to find indicators of muscle layer invasion. Comparison of indicators' diagnostic performance was done with receiver operating characteristic (ROC) curve and generalized linear model analyses. Optimal cutoff point was determined by the Youden index J.

RESULTS

Inter-reader agreement was at least substantial for VIRADS categorization (κ 0.77-0.81), and almost perfect for tumor-wall interface (intraclass correlation coefficient 0.88-0.90). Tumor-wall interface (odds ratio [OR] 1.90-2.00) and VIRADS score (OR 8.59-8.89) were independently associated with muscle layer invasion (p ≤ 0.02). For VIRADS, area under the ROC curve (AUROC) was 0.94, and the accuracy was 0.93 at score 3, the optimal threshold for predicting muscle layer invasion. Depending on the MRI sequence, tumor-wall interface showed AUROCs of 0.90-0.92 and accuracy of 0.84-0.90 at suggested thresholds (3 ± 0.3 cm). Tumor-wall interface showed insignificant differences in accuracy compared with VIRADS (p > 0.10), except as measured on diffusion-weighted images (p = 0.01).

CONCLUSIONS

VIRADS is a good predictor of muscle layer invasion. As an independent quantitative indicator, tumor-wall interface may complement VIRADS to enhance prediction.

KEY POINTS

• Vesical Imaging-Reporting and Data System (VIRADS) is a promising predictor of muscle invasion of bladder cancer with good reproducibility, as suggested by previous studies. • VIRADS score and the tumor-wall interface (curvilinear contact length between the tumor and the bladder wall) are independent predictors of muscle layer invasion. • As an easy-to-use quantitative indicator, tumor-wall interface is expected to be used as an indicator complementary to VIRADS, a qualitative indicator.

Preoperative detection of Vesical Imaging-Reporting and Data System (VI-RADS) score 5 reliably identifies extravesical extension of urothelial carcinoma of the urinary bladder and predicts significant delayed time to cystectomy: time to reconsider the need for primary deep transurethral resection of bladder tumour in cases of locally advanced disease?

OBJECTIVES

(I) To determine Vesical Imaging-Reporting and Data System (VI-RADS) score 5 accuracy in predicting locally advanced bladder cancer (BCa), so as to potentially identify those patients who could avoid the morbidity of deep transurethral resection of bladder tumour (TURBT) in favour of histological sampling-TUR prior to radical cystectomy (RC). (II) To explore the predictive value of VI-RADS score 5 on time-to-cystectomy (TTC) outcomes.

PATIENTS AND METHODS

We retrospectively reviewed patients' ineligible or refusing cisplatin-based combination neoadjuvant chemotherapy who underwent multiparametric magnetic resonance imaging (mpMRI) of the bladder prior to staging TURBT followed by RC for muscle-invasive BCa. Sensitivity, specificity, positive and negative predictive values (PPV, NPV) were calculated for VI-RADS score 5 vs. score 2-4 cases to assess the accuracy of mpMRI for extravesical BCa detection (≥pT3). VI-RADS score performance was assessed by receiver operating characteristics curve analysis. A Κ statistic was calculated to estimate mpMRI and pathological diagnostic agreement. The risk of delayed TTC (i.e. time from initial BCa diagnosis of >3 months) was assessed using multivariable logistic regression model.

RESULTS

A total of 149 T2-T4a, cN0-M0 patients (VI-RADS score 5, n = 39 vs VI-RADS score 2-4, n = 110) were examined. VI-RADS score 5 demonstrated sensitivity, specificity, PPV and NPV, in detecting extravesical disease of 90.2% (95% confidence interval [CI] 84-94.3), 98.1% (95% CI 94-99.6), 94.9% (95% CI 89.6-97.6) and 96.4% (95% CI 91.6-98.6), respectively. The area under the curve was 94.2% (95% CI 88.7-99.7) and inter-reader agreement was excellent (Κ_inter 0.89). The mean (SD) TTC was 4.2 (2.3) and 2.8 (1.1) months for score 5 vs 2-4, respectively (P < 0.001). VI-RADS score 5 was found to independently increase risk of delayed TTC (odds ratio 2.81, 95% CI 1.20-6.62).

CONCLUSION

The VI-RADS is valid and reliable in differentiating patients with extravesical disease from those with muscle-confined BCa before TURBT. Detection of VI-RADS score 5 was found to predict significant delay in TTC independently from other clinicopathological features. In the future, higher VI-RADS scores could potentially avoid the morbidity of extensive primary resections in favour of sampling-TUR for histology. Further prospective, larger, and multi-institutional trials are required to validate clinical applicability of our findings.

Staging of bladder cancer with multiparametric MRI

The distinction of non-muscle-invasive bladder cancer and muscle-invasive bladder cancer is important for the selection of the optimal treatment. Multiparametric MRI (mp-MRI) has been an useful modality for the T staging of bladder cancer, and a systematic evaluation of mp-MRI is needed. The Vesical Imaging Reporting and Data System was designed to standardize the scanning and reporting criteria based on mp-MRI for clinical and research applications. This review briefly describes the method, interpretation, and timing of mp-MRI examinations in the clinical settings. Validation studies of Vesical Imaging Reporting and Data System and future perspectives are also considered.

Overview of VI-RADS in Bladder Cancer

OBJECTIVE. The purpose of this article is to review the natural history and management of bladder cancer, with insight into MRI applications for the assessment of muscle invasiveness of bladder cancer using the newly developed Vesical Imaging Reporting and Data System (VI-RADS) score. CONCLUSION. Multiparametric MRI and the VI-RADS score have been consistently validated across several different institutions as appropriate tools for local staging of bladder cancer and have been proven to contribute to the diagnostic workup and management of urinary bladder cancer.

Use of Vesical Imaging-Reporting and Data System (VI-RADS) for detecting the muscle invasion of bladder cancer: a diagnostic meta-analysis

OBJECTIVES

To comprehensively assess the diagnostic performance of Vesical Imaging-Reporting and Data System (VI-RADS) score for detecting the muscle invasion of bladder cancer.

METHODS

PubMed, Web of Science, and Embase were searched up to November 20, 2019. QUADAS-2 tool assessed the quality of included studies. The diagnostic estimates including sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and the area under the curve (AUC) of hierarchical summary receiver operating characteristic (HSROC) were calculated. Further subgroup analysis, meta-regression and sensitivity analysis were conducted.

RESULTS

Six studies with 1064 patients were finally included. The pooled sensitivity, specificity, and AUC value were 0.90 (95% CI 0.86-0.94), 0.86 (95% CI 0.71-0.94), and 0.93 (95% CI 0.91-0.95) for VI-RADS 3 as the cutoff value. The corresponding estimates were 0.77 (95% CI 0.65-0.86), 0.97 (95% CI 0.88-0.99), and 0.92 (95% CI 0.89-0.94) for VI-RADS 4 as the cutoff value. Meta-regression analysis revealed that study design (p value 0.01) and surgical pattern of reference standard (p value 0.02) were source of the heterogeneity of pooled sensitivity. No publication bias was observed.

CONCLUSIONS

The VI-RADS score can provide a good predictive ability for detecting the muscle invasiveness of primary bladder cancer with VI-RADS 3 or VI-RADS 4 as the cutoff value.

KEY POINTS

• VI-RADS score has high sensitivity and specificity for predicting muscle invasion. • The diagnostic efficiencies of VI-RADS 3 and VI-RADS 4 as the cutoff value are similar. • VI-RADS score could be used for detecting muscle invasion of bladder cancer in clinical practice.

Diagnostic Performance of Vesical Imaging Reporting and Data System for the Prediction of Muscle-invasive Bladder Cancer: A Systematic Review and Meta-analysis

CONTEXT

A noninvasive multiparametric magnetic resonance imaging (MRI)-based scoring system for predicting muscle-invasive bladder cancer (MIBC), the "Vesical Imaging Reporting and Data System" (VI-RADS), was recently developed by an international multidisciplinary panel. Since then, a few studies evaluating the value of VI-RADS for predicting MIBC have been published.

OBJECTIVE

To review the diagnostic performance of VI-RADS for the prediction of MIBC.

EVIDENCE ACQUISITION

PubMed and EMBASE databases were searched up to November 10, 2019. We included diagnostic accuracy studies using VI-RADS to predict MIBC using cystectomy or transurethral resection as the reference standard. Methodological quality was evaluated with Quality Assessment of Diagnostic Accuracy Studies-2. Sensitivity and specificity were pooled and plotted using hierarchical summary receiver operating characteristics (HSROC) modeling. Meta-regression analyses were done to explore heterogeneity.

EVIDENCE SYNTHESIS

Six studies (1770 patients) were included. Pooled sensitivity and specificity were 0.83 (95% confidence interval [CI] 0.70-0.90) and 0.90 (95% CI 0.83-0.95), and the area under the HSROC curve was 0.94 (95% CI 0.91-0.95). Heterogeneity was present among the studies (Q = 29.442, p <  0.01; I² = 87.93%, and 90.99% for sensitivity and specificity). Meta-regression analyses showed that the number of patients (>205 vs ≤205), magnetic field strength (3 vs 1.5 T), T2-weighted image slice thickness (3 vs 4 mm), and VI-RADS cutoff score (≥3 vs ≥4) were significant factors affecting heterogeneity (p ≤  0.03).

CONCLUSIONS

VI-RADS shows good sensitivity and specificity for determining MIBC. Technical factors associated with MRI acquisition and cutoff scores need to be taken into consideration as they may affect performance.

PATIENT SUMMARY

A recently established noninvasive magnetic resonance imaging-based scoring system shows good diagnostic performance in detecting muscle-invasive bladder cancer.

The effectiveness of multiparametric magnetic resonance imaging in bladder cancer (Vesical Imaging-Reporting and Data System): A systematic review

Objective

To evaluate the role of the Vesical Imaging-Reporting and Data System (VI-RADS) score in the diagnostic pathway of bladder cancer.

Methods

A systemic search of the contemporary literature was performed in December 2019 using the Medical Literature Analysis and Retrieval System Online (MEDLINE), the Excerpta Medica dataBASE (EMBASE), and Web of Science databases focussing on all available articles on VI-RADS.

Results

Overall, six of 15 articles were included. All the available articles evaluated the ability of radiologists to use the VI-RADS score for discriminating non-muscle-invasive bladder cancer (NMIBC) from muscle-invasive bladder cancer (MIBC). Considering a cut-off VI-RADS score of >2, the sensitivity, specificity, positive (PPV) and negative predictive value (NPV) were 78-91.9%, 85-91%.1, 69-78%, and 88-97.1%, respectively. Considering a VI-RADS score cut-off of >3, the sensitivity, specificity, PPV and NPV were 77-94.6%, 43.9-96.5%, 51.6-86%, and 63.7-93%, respectively. Good interobserver agreement was demonstrated in the evaluated studies with a κ score of 0.73-0.89. Only one study evaluated the utility of VI-RADS in determining the presence of MIBC in patients treated with transurethral resection of the bladder diagnosed with high-grade T1 before the second transurethral resection using a VI-RADS score cut-off of >2; the sensitivity, specificity, PPV and NPV were 85%, 93.6%, 74.5%, and 96.6%, respectively.

Conclusion

The VI-RADS score, using multiparametric magnetic resonance imaging, showed excellent results in discriminating MIBC from NMIBC. Preliminary results have been reported for its use in patients with high-grade T1 bladder cancer. These results need to be validated in high-quality real-world settings.

Abbreviations

DCE: dynamic contrast enhancement; DWI: diffusion-weighted imaging; (N)MIBC: (non-)muscle-invasive bladder cancer; mpMRI: multiparametric MRI; TURBT: transurethral resection of bladder tumour; (N)(P)PV: (negative) (positive) predictive value; SC: structural category; T2W: T2-weighted; VI-RADS: vesical imaging-reporting and data system.

MRI of Bladder Cancer: Local and Nodal Staging

Accurate staging of bladder cancer (BC) is critical, with local tumor staging directly influencing management decisions and affecting prognosis. However, clinical staging based on clinical examination, including cystoscopy and transurethral resection of bladder tumor (TURBT), often understages patients compared to final pathology at radical cystectomy and lymph node (LN) dissection, mainly due to underestimation of the depth of local invasion and the presence of LN metastasis. MRI has now become established as the modality of choice for the local staging of BC and can be additionally utilized for the assessment of regional LN involvement and tumor spread to the pelvic bones and upper urinary tract (UUT). The recent development of the Vesical Imaging-Reporting and Data System (VI-RADS) recommendations has led to further improvements in bladder MRI, enabling standardization of image acquisition and reporting. Multiparametric magnetic resonance imaging (mpMRI) incorporating morphological and functional imaging has been proven to further improve the accuracy of primary and recurrent tumor detection and local staging, and has shown promise in predicting tumor aggressiveness and monitoring response to therapy. These sequences can also be utilized to perform radiomics, which has shown encouraging initial results in predicting BC grade and local stage. In this article, the current state of evidence supporting MRI in local, regional, and distant staging in patients with BC is reviewed. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY STAGE: 2 J. Magn. Reson. Imaging 2020;52:649-667.